Fuzzy K-means clustering models for triangular fuzzy time trajectories

We focus our attention on the classification of fuzzy time trajectories with triangular membership function, described by a given set of individuals. To this purpose, we adopt a fullyinformational approach, explicitly recognizing the informational nature shared by the ingredients of the classification procedure: the observed data (Empirical Information) and the classification model (Theoretical Information). In particular, by supposing that the informational paradigm has a fuzzy nature, we suggest three fuzzy clustering models allowing the classification of the triangular fuzzy time trajectories, based on the analysis of the cross sectional and/or longitudinal characteristics of their components (centers and spreads). Two applicative examples are illustrated.     

On Block Updating in Markov Random Field Models for Disease Mapping

Gaussian Markov random field (GMRF) models are commonly used to model spatial correlation in disease mapping applications. For Bayesian inference by MCMC, so far mainly single-site updating algorithms have been considered. However, convergence and mixing properties of such algorithms can be extremely poor due to strong dependencies of parameters in the posterior distribution. In this paper, we propose various block sampling algorithms in order to improve the MCMC performance. The methodology is rather general, allows for non-standard full conditionals, and can be applied in a modular fashion in a large number of different scenarios. For illustration we consider three different applications: two formulations for spatial modelling of a single disease (with and without additional unstructured parameters respectively), and one formulation for the joint analysis of two diseases. The results indicate that the largest benefits are obtained if parameters and the corresponding hyperparameter are updated jointly in one large block. Implementation of such block algorithms is relatively easy using methods for fast sampling of Gaussian Markov random fields ( Rue, 2001 ). By comparison, Monte Carlo estimates based on single-site updating can be rather misleading, even for very long runs. Our results may have wider relevance for efficient MCMC simulation in hierarchical models with Markov random field components.     

三维Minkowski空间中有相等主曲率函数的一类特殊曲面的位置向量场

讨论三维Minkowski空间R2 .1中一类特殊曲面在主曲率函数相等时的情形 ,给出了这类曲面在这一情形下的位置向量场     

汉语词义和词汇系统的历史演变初探——以“投”为例

词汇是一个系统,词义也是有系统性的。运用“概念要素分析法”来分析词义,可以更好地归纳词义,并厘清词义之间的联系及其历史发展。以概念场为背景,考察各个概念域中的成员及其分布在不同历史时期的演变,是研究词汇系统历史演变的一种有效的方法。     

“哲学意味”与“补史之阙”

传统上西方人为小说辩护的理由是它“更富于哲学意味” ,中国人的辩护理由是它“有可观之辞”。从文化传播的角度看 ,小说的功能正在补正统文化之缺 ,后一种理由更符合实际。文人大规模地介入小说活动 ,使小说成为沟通各种文化的公共领域。 2 0世纪以后 ,西方出现了将哲学“非中心化”的主张 ;从鲁迅开始 ,中国现代小说摆脱“历史癖” ,强化了批判精神。当代小说仍应发挥传统 ,沟通文人的批判意识和民众智慧 ,采取积极策略     

英语功能语法学与英语教学

不同于传统语法所提供的各种语法规则,功能语法学是一种非常丰富的语言描述方法,它关注语言在各种社会语境中使用的不同形态;并且还观察语言所承担的各种社会功能以及对读者或听众所产生的影响。它应当被当成是传统语法的丰富和补充。同时,功能语法提供给教师的是一种很有效的深入理解语篇的方法,并为提高教学质量提供了很多启示。     

Three-level main-effects designs exploiting prior information about model uncertainty

To explore the projection efficiency of a design, Tsai, et al [2000. Projective three-level main effects designs robust to model uncertainty. Biometrika 87, 467–475] introduced the Q criterion to compare three-level main-effects designs for quantitative factors that allow the consideration of interactions in addition to main effects. In this paper, we extend their method and focus on the case in which experimenters have some prior knowledge, in advance of running the experiment, about the probabilities of effects being non-negligible. A criterion which incorporates experimenters’ prior beliefs about the importance of each effect is introduced to compare orthogonal, or nearly orthogonal, main effects designs with robustness to interactions as a secondary consideration. We show that this criterion, exploiting prior information about model uncertainty, can lead to more appropriate designs reflecting experimenters’ prior beliefs.     

Communication of risk: health hazards from mobile phones

Summary. Possible health hazards from mobile phones arise from the use of the phones themselves and via the base stations that relay signals. Except for an increase in traffic accidents induced by the use of mobile phones in cars the evidence for a health hazard is at most indirect, but it cannot be entirely dismissed; the phones have not been widely used for sufficiently long for direct epidemiological studies to have high sensitivity for detecting any induced incidence of cancer, for example. The background and evidence are briefly reviewed and the steps taken in the UK to make information widely available described.     

钢管相邻缺陷漏磁场相互影响的分析

实际工况中的管道缺陷是非常复杂的,用物理试验的方法研究各种缺陷漏磁场的变化规律有一定的难度。该文针对油气管道常用的钢管缺陷产生的漏磁场建立了三维有限元模型,采用有限元方法计算了几种相邻缺陷的漏磁场模型,给出了计算结果,并分析了各种相邻缺陷对漏磁场信号的影响。结果表明当相邻缺陷的中心线与磁场方向平行时,对缺陷漏磁信号的影响最小;组合型的缺陷对漏磁信号的影响最大。     

论张岱小品文的世俗性

从审美的角度看，张岱的小品文卸去了“文以载道”的传统，以普通人的视角再现明亡之前其亲历的生活，多方面表现了大众风情，具有鲜明的世俗性：把在传统文人看来俗之又俗的生活素材诉诸笔端；牵引市民化的人物走进小品文；尤其小说化语言的运用，使得作品富于生活气息。究其成因，首先是文艺思潮世俗化的时代洪流。涌溢各处、不断浸淫；其次是当时市民阶层爱好并喜做小品文的风气甚炽，使得张岱需要考虑读者的趣味；再次是张岱家世生平的坎坷，使他处于文化边缘的写作境地，用饱含深情的笔墨展现市民形貌、礼赞世俗人生。